1. Field of the Invention
The present invention relates to an electronic still camera which has a continuous photographing function for performing successive photographing for a plurality of times in response to a request for photographing.
2. Description of the Related Art
Recently, data size of a photographic image is showing a tendency to increase as the number of pixels of an electronic still camera increases, and it is a significant challenge to usefully use a memory area of an image storage medium for storing the photographic image. As a technique for saving the memory area of the image storage medium, a cropping function which cuts out a necessary part of the photographic image simultaneously with photographing and stores only the cut-out image in the image storage medium is known.
In Japanese Unexamined Patent Application Publication No. 2001-236497, for example, a method of automatically performing cropping or zooming operation around a main subject (photographic subject) whose image is being captured, based on contents of a photographing scene, is proposed. Further, according to a program “XV” which is developed at University of Pennsylvania in the United States, a cropped image is obtained by removing a uniform margin at the boundary of the image.
However, applying the cropping function to continuous photographing is not considered according to the conventional electronic still camera, and hence it is impossible to change the size of an area to be cut out (cropping area) for every photographing in the continuous photographing. Therefore, when a moving body is subjected to the continuous photographing, data size of its image to be stored in the image storage medium is the same in any photographing in the continuous photographing, although the size of the moving body with respect to an image screen changes over time. As a result of this, when a moving body which moves away from a photographer is subjected to the continuous photographing, for example, the size of the moving body with respect to the image screen becomes smaller over time, and hence the memory area of the image storage medium is wastefully used. Therefore, the number of recordable photographic images at the time of continuous photographing decreases. On the other hand, when a moving body which moves closer to the photographer is subjected to the continuous photographing, the size of the moving body with respect to the image screen becomes larger over time, and hence the size of the subject image may become larger than the set cropping area.
Moreover, according to the cropping methods of the Japanese Unexamined Patent Application Publication No. 2001-236497 and the program “XV”, cropping of a characteristic part in the photographic image is possible, but cropping while paying attention to the moving photographic subject only is impossible.